Dishwasher diverter valves with continuous calibration

Abstract

Diverter valves and associated dishwashers with continuous calibration are provided. An example dishwasher includes a diverter valve assembly. The diverter valve assembly is configured to output a signal having a plurality of pulses. Each of the plurality of pulses has an activation time indicative of movement of the diverter valve assembly into one of a plurality of positions. The dishwasher performs operations including receiving the signal from the diverter valve assembly and determining a current activation time associated with the most recent pulse exhibited by the signal. The operations include determining a current position of the plurality of positions based at least in part on the current activation time and a plurality of average activation times respectively associated with the plurality of positions. The operations include, after determining the current position, updating the average activation time associated with the current position based at least in part on the current activation time.

What is claimed is: 
     
       1. A dishwasher comprising:
 a tub; 
 a cabinet; 
 a wash chamber; 
 one or more racks; 
 a diverter valve assembly, wherein the diverter valve assembly is configured to output a signal having a plurality of pulses, each of the plurality of pulses having an activation time, the activation time of each of the plurality of pulses being the length of time for which each of the plurality of pulses exist, the activation time being indicative of movement of the diverter valve assembly into one of a plurality of positions respectively corresponding to a plurality of patterns of liquid flow in the dishwasher; 
 one or more processing devices; and 
 a non-transitory computer-readable medium storing instructions that, when executed by the one or more processing devices, cause the one or more processing devices to perform operations, the operations comprising: 
 receiving the signal from the diverter valve assembly; 
 determining a current activation time associated with the most recent pulse exhibited by the signal; 
 determining a current position of the plurality of positions based at least in part on the current activation time and a plurality of average activation times respectively associated with the plurality of positions; 
 after determining the current position, updating the average activation time associated with the current position based at least in part on the current activation time; and 
 operating the diverter valve assembly based on the activation time to achieve continuous calibration of the diverter valve assembly. 
 
     
     
       2. The dishwasher of  claim 1 , wherein determining the current position of the plurality of positions based at least in part on the current activation time and the plurality of average activation times respectively associated with the plurality of positions comprises:
 determining one or more threshold times for each of the plurality of positions based at least in part on the average activation time associated with such position. 
 
     
     
       3. The dishwasher of  claim 2 , wherein determining the one or more threshold times for each of the plurality of positions based at least in part on the average activation time associated with such position comprises:
 determining a maximum activation time and a minimum activation time for each of the plurality of positions based at least in part on the average activation time associated with such position. 
 
     
     
       4. The dishwasher of  claim 3 , wherein:
 the maximum activation time for each of the plurality of positions comprises the average activation time for such position multiplied by a first number that is greater than one; and 
 the minimum activation time for each of the plurality of positions comprises the average activation time for such position multiplied by a second number that is less than one. 
 
     
     
       5. The dishwasher of  claim 3 , wherein:
 the maximum activation time for each of the plurality of positions comprises a first midpoint between the average activation time for such position and a next greatest average activation time associated with one of the plurality of positions; and 
 the minimum activation time for each of the plurality of positions comprises a second midpoint between the average activation time for such position and a next least average activation time associated with one of the plurality of positions. 
 
     
     
       6. The dishwasher of  claim 3 , wherein determining the current position of the plurality of positions based at least in part on the current activation time and the plurality of average activation times respectively associated with the plurality of positions further comprises:
 classifying the current position as the position for which the current activation time is between the maximum activation time and the minimum activation time. 
 
     
     
       7. The dishwasher of  claim 1 , wherein updating the average activation time associated with the current position based at least in part on the current activation time comprises:
 entering the average activation time and the current activation time into a weighted average formula to calculate an updated average activation time for the current position. 
 
     
     
       8. The dishwasher of  claim 1 , wherein the operations further comprise performing a calibration routine to obtain the plurality of average activation times respectively associated with the plurality of positions. 
     
     
       9. The dishwasher of  claim 8 , wherein the calibration routine comprises:
 cycling the diverter valve assembly through each of the plurality of positions; 
 determining a plurality of initial activation times exhibited by the signal when the diverter valve is respectively cycled through the plurality of positions; and 
 determining the plurality of average activation times respectively associated with the plurality of positions based on the plurality of initial activation times. 
 
     
     
       10. The dishwasher of  claim 9 , wherein determining the plurality of initial activation times exhibited by the signal when the diverter valve is respectively cycled through the plurality of positions comprises:
 sorting the plurality of initial activation times into a sequence by magnitude; and 
 respectively assigning the plurality of initial activation times to the plurality of positions based on the sequence. 
 
     
     
       11. The dishwasher of  claim 1 , wherein the dishwasher valve assembly comprises:
 a diverter valve, wherein the diverter valve can be oriented in the plurality of positions respectively corresponding to the plurality of patterns of liquid flow in the dishwasher; 
 a cam rotatably mounted within the diverter valve assembly, wherein the cam has a plurality of protrusions along an outer edge of the cam, the plurality of protrusions having a plurality of different angular lengths, each of the plurality of protrusions having a rising edge and a falling edge, and wherein the falling edge of each of the plurality of protrusions is located at a first point in a rotational path of the outer edge of the cam when the diverter valve is oriented in a respective one of the plurality of positions; and 
 a protrusion sensor configured to output the signal having the plurality of pulses, each of the plurality of pulses being indicative of the presence of one of the plurality of protrusions at the first point in the rotational path.